http://www.handhelds.org/moin/moin.cgi/A636
Pinout
1 jtec? TRST?
2 jtec? TCK?
3 jtec? TDO?
4 jtec? TMS?
5 jtec? TDI?
6 GRND
7 speaker monoout
8 ?
9 rs232 rin2
10 rs232 rin3
11 rs232 dout2
12 rs232 dout3
13 rs232 rin4
14 rs232 dout1
15 rs232 rin1
16 ?
17 usb GRND
18 usb data+
19 usb data-
20 usb VCC (+5v VDC)
21 GRND
22 DC+ 5v
23 DC+ 5v
24 DC+ 5v
25 DC+ 5v
26 GRND
It is possible that Asus mypal A632 is pincompatable
The rs232 pin numbering is from the MA3243C chip.
Not certain of jtec, but looking at mypal620 pins it could be